Advanced Copy function Partial copying - SnapOPC / SnapOPC+

SnapOPC only copies the "before" picture of data being updated, to the copy volume. By only copying data subject to change, copy volume capacity can be much smaller than the original business data volume. In addition, SnapOPC+ provides generation management of the updated data. The difference between SnapOPC+ and SnapOPC is that SnapOPC+ updates data only as history information while SnapOPC stores the data redundantly. Logging as history information can provide disk based generation backup using a smaller copy volume capacity.